石油学报 ›› 2020, Vol. 41 ›› Issue (9): 1109-1116.DOI: 10.7623/syxb202009007

• 油田开发 • 上一篇    下一篇

高含水致密凝析气藏特殊相态变化

谢军1, 李骞2, 涂汉敏3, 赵梓寒2   

  1. 1. 中国石油天然气集团有限公司规划计划部 北京 100007;
    2. 中国石油西南油气田公司勘探开发研究院 四川成都 610041;
    3. 西南石油大学油气藏地质及开发工程国家重点实验室 四川成都 610500
  • 收稿日期:2019-11-11 修回日期:2020-05-13 出版日期:2020-09-25 发布日期:2020-09-29
  • 通讯作者: 李骞,男,1984年1月生,2006年获成都理工大学学士学位,2013年获中国石油大学(北京)博士学位,现为中国石油西南油气田公司勘探开发研究院高级工程师,主要从事复杂气藏开发机理、开发动态预测、数值模拟等方面的研究工作。Email:liqian05@petrochina.com.cn
  • 作者简介:谢军,男,1968年2月生,1988年获西南石油学院学士学位,现为中国石油天然气集团有限公司规划计划部教授级高级工程师,主要从事常规和非常规油气开发管理及研究工作。Email:xiejun01@petrochina.com.cn
  • 基金资助:

    中国石油天然气集团公司科技重大专项(2016E-06)和国家科技重大专项(2016ZX05052)资助。

Special phase behavior of high water-containing tight condensate gas reservoir

Xie Jun1, Li Qian2, Tu Hanmin3, Zhao Zihan2   

  1. 1. Planning Department, China National Petroleum Corporation, Beijing 100007, China;
    2. Research Institute of Exploration and Development, PetroChina Southwest Oil&Gas Field Company, Sichuan Chengdu 610041, China;
    3. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Sichuan Chengdu 610500, China
  • Received:2019-11-11 Revised:2020-05-13 Online:2020-09-25 Published:2020-09-29

摘要:

高含水致密凝析气藏具有储层低孔、致密、含水饱和度高的特征,在其开发过程中,当压力降低至露点压力以下,流体会发生复杂的相态变化,析出凝析油,形成油、气、水三相渗流,导致渗流阻力进一步增大。与常规凝析气藏相比,高含水致密凝析气藏开发过程中相态变化具有特殊性:①储层含水饱和度较高,水相会影响流体的相态变化;②由于储层致密、流体复杂,井底附近渗流阻力较大,压降漏斗陡峭,流体相态表现出强非平衡相态变化特征,这与常规凝析气藏平衡相变特征存在明显差异。基于室内PVT筒实验、长岩心驱替实验及非平衡相态理论,系统研究了高含水致密凝析气藏的相态变化特殊规律。研究结果表明:①水相会降低凝析气藏的露点压力,增大反凝析油饱和度;②凝析气藏存在"凝析滞后"现象,非平衡相变效应可降低凝析油饱和度;③针对受地层水影响较小的气井可增大生产压差采出更多的凝析油。针对特殊相变特征,研究结果可以为高含水致密凝析气藏开发过程中制定合理的生产压差提供依据。

关键词: 高含水, 致密储层, 凝析气藏, 非平衡相态, 合理生产压差

Abstract:

High water-containing tight condensate gas reservoirs are characterized by tight reservoirs with low porosity and high water saturation. During the development process, when the pressure drops below the dew point pressure, the fluid will undergo complex phase behavior, precipitate condensate and form the three phase percolation of oil, gas and water, which leads to a further increase in percolation resistance. Compared with conventional condensate gas reservoirs, the phase behavior in high water-containing tight condensate gas reservoirs have the particularity during development. First, the water saturation of reservoirs is high, and the water phase will affect the phase behavior of fluids; second, due to the tight reservoir, complex fluids, high percolation resistance near the bottom hole and steep pressure drop funnel, the fluids show strong non-equilibrium phase transition, which is obviously different from the equilibrium phase transition in conventional condensate gas reservoirs. Based on the laboratory experiment of PVT cell, the long core displacement experiment and the theory of non-equilibrium phase, this paper systematically analyzes the special law of phase transition in high water -containing tight condensate gas reservoirs. The results show that:(1) the water phase will reduce the dew point pressure of the condensate gas reservoir and increase the retrograde gas condensate saturation; (2) there is a lag in gas condensation in the condensate gas reservoir, and the non-equilibrium phase behavior effect can reduce the condensate saturation;(3) for the gas wells less affected by formation water, more gas condensate can be produced by increasing the production pressure difference. Thus, according to the characteristics of special phase behavior, this can provide a basis for determining a reasonable production pressure difference for the exploration of high water-containing tight condensate gas reservoirs.

Key words: high water cut, tight reservoir, condensate gas reservoir, non-equilibrium phase, reasonable production pressure difference

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